1. Field of the Invention
This invention relates to a processing operation workbench, particularly to one provided with an adjusting device for lifting and lowering the workbench.
2. Description of the Prior Art
General processing operation will employ a workbench for placing a work piece to be processed to facilitate carrying out processing work. For instance, an abrasive belt machine used for woodwork grinding is provided with a workbench, and the workbench of a general abrasive belt machine is fitted thereon with a conveyer belt that is correspondingly provided with an abrasive belt wheel set so that when a work piece to be ground and processed is set on the conveyer belt, the work piece can be ground and processed by the abrasive belt wheel set.
However, after the conventional abrasive belt machine is used for a certain time and worn away and when the abrasive belt wheel set has to be replaced with a new one, or when the abrasive belt machine needs to be corrected and adjusted, the screwing fasteners that control tightness of the abrasive belt wheel set must be adjusted and corrected. But, the abrasive belt wheel set of the conventional abrasive belt machine is quite heavy and the screwing fasteners that lock the abrasive belt wheel set are numerous; therefore, when correcting and adjusting the abrasive belt machine, an operator usually has to waste much time and thus will influence work progress and greatly lower work efficiency. In view of such situation, the inventor of this invention, who has been engaged in production and marketing of related products for many years and has accumulated much technique and experience, actively carries out a research for ameliorating the defects of the conventional abrasive belt machine and hence devises this invention.